Members of Yuen Long District Council and the local government-appointed Area Committee on Wednesday criticised authorities for not sending out an emergency alert to residents after a power cable bridge fire last week led to a massive power outage.

The members said many residents in Yuen Long and Tin Shui Wai were left wondering what had happened on the night of June 21 when their buildings were plunged into darkness.

"It may be an accident this time. But what if it's a terrorist attack or use of a drone to attack the power network. I am not sure if CLP has prepared for it ... I originally thought the fire was a terrorist attack. Why did the bridge catch fire out of the blue as it has never happened for 10 or 20 years," asked Lau Sik-man, an Area Committee member from Tin Shui Wai North.

At a special joint-meeting, members also questioned why the government's HK$100 million mobile phone emergency alert system can't issue district based messages. They also asked CLP why power was resumed to some buildings quicker than others.

In response, CLP officials said power supply is a complicated matter, urging members to wait for its final report. The officials also said new power cables have been laid after the fire and power supply is back to normal.

The officials didn't address questions as to whether they will compensate those residents affected by the blackout.

The Fire Services Department told the meeting that an investigation into the fire confirmed that foul play wasn't involved, but it was still trying to determine the cause.

The Communications Authority noted that some mobile phone transmitters aren't equipped with back up power because of safety concerns and said it will follow up with operators on how they can improve this situation.

The authority also said people would not be able to receive an emergency alert from the government if their mobile phone didn't have any signal.

Yuen Long District Officer Gordon Wu said the government will review the way information was disseminated on the day in question.